In　the　application　process　of　wireless　charging　for　electric　vehicles,　foreign　object　detection　(FOD)　is　one　of　the　necessary　measures　to　address　safety　issues.　This　letter　proposes　a　self-resonant　FOD　method　for　metal　object　(MO)　and　living　object　(LO)　detection.　It　is　possible　to　detect　an　MO　and　an　LO　without　being　affected　by　the　85-kHz　power　transmission,　without　the　need　for　a　detection　coil　specifically　designed　to　decouple　from　the　power　transmission　coil　and　a　high-pass　filter.　Each　self-resonant　detection　coil　consists　of　a　unipolar　coil　and　a　comb-shaped　capacitor　plate.　This　letter　describes　a　method　that　can　identify　an　MO　and　an　LO　by　scanning　frequencies　within　a　small　range　and　detecting　the　slope　of　the　output　voltage　as　it　changes　with　frequency.　When　there　are　no　foreign　objects,　the　absolute　value　of　the　output　voltage　slope　is　less　than　0.15.　The　voltage　slope　less　than　-0.15　indicates　the　presence　of　MOs,　while　a　slope　greater　than　0.15　indicates　the　presence　of　an　LO.　To　verify　the　feasibility　of　the　proposed　method,　an　experimental　prototype　has　been　constructed.　　©　1986-2012　IEEE.